The present invention relates to a microorganism producing teicoplanin and a fermentation process for preparing teicoplanin in an aerobic condition, using an isolated mutant strain belonged to Actinoplanes teichomyceticus species on the culture medium containing assimilable carbon, nitrogen sources and mineral salts.
In particular, the present invention concerns to an isolated mutant strain Actinoplanes teichomyceticus BNG 2315 (KCCM-10601) producing teicoplanin more than about sixty times productivity than those of described in the prior arts (U.S. Pat. No. 4,239,751) as well as a fermentation process for preparing teicoplanin in an aerobic condition using the said mutant strain.
Teicoplanin, one of antibiotics produced by Actinoplanes teichomyceticus, has been classified from the vancomycin-ristocetin family of glycopeptide antibiotics. Its mechanism is to inhibit the cell wall biosynthesis and it has been administered against gram-positive antibiotics-resistant pathogens, such as, methicillin-resistant Staphylococcus aureus, coagulase-negative Staphylococci, Clostridia, and Enterococci. 
The emergence of microorganisms resistant to various kinds of antibiotics, especially, methicillin-resistant microorganisms caused by administration of too much antibiotics may result in severe health problem. Further, the methicillin-resistant microorganism is also resistant against any other antibiotics, such as, aminoglycosides, tetracyclines, cephalosporins, cephamycins, penems, carbapenems, and macrolides, which causes the severe disease.
World-wide problem of the protection from methicillin-resistant S. aureus have resulted in the increased use of vancomycin and teicoplanin, those are, the only agents for effective treatment of these pathogens.
Teicoplanin is an antibiotic produced by cultivating the strain Actinoplanes teichomyceticus nov. sp. (ATCC-31121) in a culture medium containing the carbon source, nitrogen source and inorganic salts (J. Antibiotics, 276-283, 1978; U.S. Pat. No. 4,239,751). However, the strain described in the U.S. Pat. No. 4,239,751 is undesirable in a commercialized scale, because it produces teicoplanin less than 50 mg/L productivity in a high cost.
Thus, the isolation of mutant strain having higher productivity in comparison to those producing teicoplanin has been required, as well as the development of fermentation process for preparing teicoplanin in an aerobic condition using said mutant strain.
Surprisingly, in the course of our screening research for teicoplanin-producing strains of Actinomycetales of the family Actinoplanaceae, we have isolated a novel strain from a soil sample collected at Sorak Mountain, Korea. Said isolated strain produces teicoplanin about 20 times productivity than those of described in prior art (U.S. Pat. No. 4,239,751).
This strain has been subjected under repeated mutagenic treatment. Then, teicoplanin-resistant mutants were isolated. The mutant strain produces teicoplanin about 60 times productivity than those described in the U.S. Pat. No. 4,239,751.